94 lines
1.7 KiB
C++
94 lines
1.7 KiB
C++
#include <bits/stdc++.h> // {{{
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#include <version>
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#ifdef __cpp_lib_ranges_enumerate
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#include <ranges>
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namespace rv = std::views;
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namespace rs = std::ranges;
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#endif
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// https://codeforces.com/blog/entry/96344
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#pragma GCC optimize("O2,unroll-loops")
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#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
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using namespace std;
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using i16 = int16_t;
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using u16 = uint16_t;
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using i32 = int32_t;
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using u32 = uint32_t;
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using i64 = int64_t;
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using u64 = uint64_t;
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using f64 = double;
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using f128 = long double;
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#if __cplusplus >= 202002L
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template <typename T> constexpr T MIN = std::numeric_limits<T>::min();
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template <typename T> constexpr T MAX = std::numeric_limits<T>::max();
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#endif
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#ifdef LOCAL
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#define db(...) std::print(__VA_ARGS__)
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#define dbln(...) std::println(__VA_ARGS__)
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#else
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#define db(...)
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#define dbln(...)
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#endif
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// }}}
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vector<u32> parities(200000, 0);
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vector<bitset<32>> present(200000);
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void solve() {
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u32 n;
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cin >> n;
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string s;
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for (u32 i = 0; i < n; ++i) {
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cin >> s;
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for (auto c : s) {
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parities[i] ^= 1 << (c - 'a');
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present[i].set(c - 'a');
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}
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}
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u64 ans = 0;
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unordered_map<u32, u64> f;
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for (u32 c = 0; c < 26; ++c) {
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u32 mask = ((1 << 26) - 1) ^ (1 << c);
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for (u32 i = 0; i < n; i++) {
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if (present[i].test(c))
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continue;
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ans += f[parities[i] ^ mask];
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++f[parities[i]];
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}
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f.clear();
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}
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cout << ans << '\n';
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}
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int main() { // {{{
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std::cin.exceptions(std::cin.failbit);
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#ifdef LOCAL
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std::cerr.rdbuf(std::cout.rdbuf());
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std::cout.setf(std::ios::unitbuf);
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std::cerr.setf(std::ios::unitbuf);
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#else
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std::cin.tie(nullptr)->sync_with_stdio(false);
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#endif
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u32 tc = 1;
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// std::cin >> tc;
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for (u32 t = 0; t < tc; ++t) {
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solve();
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}
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return 0;
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}
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// }}}
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